This invention relates to an air duct arranged to be incorporated in a fascia panel of a motor vehicle, and also to a method for making it.
A motor vehicle fascia panel usually contains at least one duct for air distribution which is arranged to be supplied with a stream of treated air coming from a heating and ventilating, and/or air conditioning, apparatus, and to deliver this treated air to vents which are open in selected places in the cabin of the vehicle.
These vents usually include de-icing vents for de-icing and de-misting the windscreen and where appropriate side windows of the vehicle. The vents also include ventilating vents which are disposed on a front part of the fascia panel and consist of side vents and at least one central vent.
Most known fascia panels contain a plurality of ducts, generally of plastics material, which are interposed between the heating and ventilating and/or air conditioning apparatus and the various vents.
The de-icing and de-misting vents are generally supplied through ducts of plastics material which are fixed underneath the armature of the fascia panel and connected to a diffuser, which is also of plastics material and which is again fixed on the armature of the fascia panel and arranged to be connected to the outlet of the heating and ventilating and/or air conditioning apparatus.
Similarly, the ventilating vents are generally supplied through ducts of plastics material which are assembled mechanically and which are fixed underneath the armature of the fascia panel and connected to a further diffuser.
Thus the diffusion of air in these known fascia panels necessitates a multiplicity of ducts and connections interposed between the heating and ventilating and/or air conditioning apparatus and the vents. This gives rise to a certain number of disadvantages: possible leaks because of the connections, air noise (vibrations in the walls of the tubes), heat losses, air pressure losses, a large number of components, occupation of much space within the fascia panel, a long and complicated fitting process, and as a result high cost.
It is also known from the publication DE-3 818 666 to provide a fascia panel which includes an integral air distribution channel. This channel is made in the form of a single member which is fixed on the underside of the fascia panel. This known solution does indeed enable the number of components to be reduced, but nevertheless it has most of the disadvantages mentioned above, due in particular to the fact that the air distribution channel is not formed in one piece with the fascia panel.
Up to the present time all attempts to make a fascia panel which includes one or more integral air ducts have been unable truly to succeed, in view particularly of the problems posed by moulding of hollow parts with complex forms.